RESUMEN

This study aimed to precisely investigate the effects of intensive physical exercise on retinal microvascular regulation in healthy volunteers through adaptive optics retinal camera (AO) measurement. We included healthy volunteers (11 men and 14 women) aged 20.6 ± 0.9. The heart rate (HR) and systolic and diastolic blood pressures (SBP, DBP) were recorded before and after a submaximal physical exertion of continuously riding a training ergometer. The superior temporal retinal artery measurements were captured using the AO-rtx1TM (Imagine Eyes, Orsay, France) without pupil dilation. We compared measures of vessel diameter (VD), lumen diameter (LD), two walls (Wall 1, 2), wall-to-lumen ratio (WLR), and wall cross-sectional analysis (WCSA) before and immediately after the cessation of exercise. Cardiovascular parameter results: After exercise, SBP, DBP, and HR changed significantly from 130.2 ± 13.2 to 159.7 ± 15.6 mm Hg, 81.2 ± 6.3 to 77.1 ± 8.2 mm Hg, and 80.8 ± 16.1 to 175.0 ± 6.2 bpm, respectively (p < 0.002). Retinal microcirculation analysis showed no significant decrease in LD, Wall 1 after exercise: from 96.0 ± 6.8 to 94.9 ± 6.7 (p = 0.258), from 11.0 ± 1.5 to 10.4 ± 1.5 (p = 0.107), respectively, and significant reduction in VD from 118.5 ± 8.3 to 115.9 ± 8.3 (p = 0.047), Wall 2 from 11.5 ± 1.0 to 10.7 ± 1.3 (p = 0.017), WLR from 0.234 ± 0.02 to 0.222 ± 0.010 (p = 0.046), WCSA from 3802.8 ± 577.6 to 3512.3 ± 535.3 (p = 0.016). The AO is a promising technique for investigating the effects of exercise on microcirculation, allowing for the tracking of changes throughout the observation. Intensive dynamic physical exertion increases blood pressure and heart rate and causes the vasoconstriction of small retinal arterioles due to the autoregulation mechanism.

RESUMEN

OBJECTIVES: To assess dietary supplements, functional foods and nutraceuticals use among the patients after myocardial infarction (MI). MATERIAL AND METHODS: The authors prospectively enrolled 100 consecutive patients hospitalized due to MI and remaining under coordinated outpatient care after MI in the authors' cardiology department. RESULTS: The authors showed that patients within median (interquartile range) 12.30 (10.18-14.57) months after MI use dietary supplements, nutraceuticals and functional foods in their everyday diet. Vitamins (53% patients), especially vitamin D (35%), were the most frequently used dietary supplements. In contrary to common usage of dietary supplements (59%), smaller proportion of patients use functional foods (21%) and nutraceuticals (5%), especially phytosterols. The authors found that the use of over-the-counter (OTC) drugs and dietary supplements is associated with age (participants <60 years old vs. participants ≥60 years old: OTC drugs: N = 8 [20.0%] vs. N = 32 [53.3%], p < 0.001; herbals: N = 3 [7.5%] vs. N = 16 [26.7%], p = 0.019), sex of the patients following MI (females vs. males: vitamins: N = 17 [70.8%] vs. N = 36 [47,4%], p = 0.045; vitamin D: N = 13 [54.2%] vs. N = 22 [28.9%], p = 0.024; omega-3 fatty acids: N = 3 [12.5%] vs. N = 1 [1.3%], p = 0.042; herbals: N = 8 [33.3%] vs. N = 11[14.5%], p = 0.040), as well as the BMI of the participants (BMI < 24.9 vs. BMI ≥ 25.0: multivitamin/ multimineral dietary supplements: N = 3 [15.0%] vs. N = 31 [42.5%], p = 0.035; vitamin B6: N = 1 [5.0%] vs. N = 21 [28.8%], p = 0.035). In the study group all participants with the age above retirement age have already withdrawn from professional activity and they more often used OTC drugs (N = 14 [25.9%] before retirement age vs. N = 26 [56.5%] above retirement age, p = 0.002). CONCLUSIONS: The patients following MI use supplements, functional foods and nutraceuticals. Their use depends on sex, age, BMI and professional activity. The authors believe that their potential beneficial effects require further evaluation in clinical longitudinal studies. Int J Occup Med Environ Health. 2023;36(6):732-43.

Asunto(s)

Alimentos Funcionales , Infarto del Miocardio , Masculino , Femenino , Humanos , Persona de Mediana Edad , Proyectos Piloto , Índice de Masa Corporal , Suplementos Dietéticos/efectos adversos , Vitaminas/uso terapéutico , Vitamina D , Medicamentos sin Prescripción

RESUMEN

Pro-inflammatory milieu of chronic kidney disease (CKD) results in endothelial damage and contributes to increased cardiovascular risk. The aim of the study was to evaluate association between neutrophil-to-lymphocyte ratio (NLR) and plasma relative expression of endothelially abundant miR-126-3p with circadian blood pressure (BP) pattern in CKD patients. This single-center observational study involved CKD stage 1-5 patients and healthy age- and sex-matched control subjects. All study participants had 24-h automatic blood pressure measurement (ABPM) performed. Plasma miRNA was quantified by qRT-PCR, in relation to endogenous U6 snRNA. In total, 90 CKD patients (60 ± 14 years, 52% males, 33 renal transplant recipients) and 25 healthy control subjects (55 ± 13 years, 48% males, p > 0.05) were enrolled in the study. We observed a positive correlation between miR-126-3p and average nighttime SBP (rho = 0.27, P = 0.02), average nighttime DBP (rho = 0.32, P = 0.003), night-day SBP ratio (ND-SBP), rho = 0.23, P = 0.03 and night-day DBP ratio (ND-DBP), rho = 0.26, P = 0.02. A positive association was found between NLR and average nighttime SBP (rho = 0.25, P = 0.01), ND-SBP (rho = 0.26, P = 0.006), and ND-DBP (rho = 0.28, P = 0.03). In the multiple regression model, NLR remained an independent predictor of average nighttime SBP (Beta per log change of NLR [95% CI]: 11.2 [1.8-10.6], P = 0.02), whereas miR-126-3p of nighttime DBP (1.88 [0.48; 3.28], p = 0.009), The results of our study point towards a link between both NLR and miR-126-3p and nighttime hypertension in CKD patients.

Asunto(s)

Hipertensión , MicroARNs , Insuficiencia Renal Crónica , Presión Sanguínea , Monitoreo Ambulatorio de la Presión Arterial , Ritmo Circadiano , Estudios Transversales , Femenino , Humanos , Linfocitos , Masculino , Neutrófilos

RESUMEN

It is well known that obesity contributes to the development of systemic inflammatory responses, which in turn may be involved in the process of interstitial fibrosis and left ventricular (LV) remodelling. Activation of pro-inflammatory factors such as transforming growth factor ß (TGF-ß) can directly stimulate mitogen-activated protein kinase (MAPK) p38 and JNK. The aim of the study was to evaluate the level of TGF-ß and MAPK p38 and JNK in the LV in Sprague Dawley (SPRD) rats maintained on a high fat diet (HFD). The SPRD rats from 4 weeks of age were on a normal fat diet (NFD) or a HFD for 12 weeks (NFD-16-week-old rats, NFD 16-wk; or HFD-16-week-old rats, HFD 16-wk) or 16 weeks (NFD-20-week-old rats, NFD 20-wk; or HFD-20-week-old rats, HFD 20-wk). At the end of the experiment, blood and LV were collected from all rats for further analysis (biochemical, Real Time PCR and immunohistochemical analysis). TGF-ß mRNA expression did not differ between the study groups of rats. However, p38 MAPK mRNA expression was significantly lower in the HFD 20-wk rats than in both the HFD 16-wk rats and the NFD 20-wk rats. c-jun mRNA expression was significantly higher in the HFD 16-wk rats than in the NFD 16-wk rats. There was significantly lower expression of c-jun mRNA in the HFD 20-wk rats and in the NFD 20-wk rats than in the HFD 16-wk rats and in the NFD 16-wk rats, respectively. TGF-ß type II receptor (TßRII) protein demonstrated only cytoplasmic reactivity, while p38 MAPK protein and c-jun protein showed both nuclear and cytoplasmic reactivity. The results suggest that a high fat diet and in two time intervals significantly influence the expression of p38 MAPK and JNK in the LV. However, demonstrating their potential involvement in the processes of interstitial myocardial fibrosis and left ventricular remodeling requires further research.

Asunto(s)

Dieta Alta en Grasa/efectos adversos , Cardiopatías/metabolismo , Ventrículos Cardíacos/metabolismo , Miocardio/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Fibrosis/metabolismo , Masculino , Obesidad/metabolismo , Ratas , Factor de Crecimiento Transformador beta/metabolismo

RESUMEN

BACKGROUND/AIMS: Chronic kidney disease is a pro-inflammatory condition where the interplay between different regulatory pathways and immune cells mediates an unfavorable remodeling of the vascular wall and myocardial hypertrophy. These mechanisms include the action of CXCL12. The aim of this study is to evaluate the association between serum CXCL12 with left ventricular hypertrophy (LVH) and blood pressure control in chronic kidney disease (CKD) patients. METHODS: This single-center observational study involved 90 stable CKD stage 1-5 patients (including 33 renal transplant recipients) and 25 healthy age- and sex-matched control subjects. CXCL12 was quantified by ELISA. 24-h ambulatory blood pressure monitoring was performed in 90 patients and 25 healthy controls. Left ventricular mass index (LVMI) was calculated based on the transthoracic echocardiography measurements in 27 patients out of the CKD population and in the whole control group. RESULTS: CXCL12 correlated significantly with LVMI by multivariate regression analysis (coefficient B = 0.33, p = 0.02) together with age (B = 0.30, p = 0.03) and gender (B = 0.41, p = 0.003). A positive correlation was observed between CXCL12 and average 24-h systolic blood pressure (SBP) (rho = 0.35, p = 0.001), daytime SBP (rho = 0.35, p = 0.001), and nocturnal SBP (rho = 0.30, p = 0.002). Nocturnal hypertension was frequent (46% of CKD patients). CONCLUSIONS: The results of our study point towards a link between CXCL12 and LVH as well as blood pressure control among patients with CKD, supporting the thesis that CXCL12 may be regarded as a new potential uremic toxin.

Asunto(s)

Quimiocina CXCL12/sangre , Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/complicaciones , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/complicaciones , Adulto , Anciano , Antihipertensivos/uso terapéutico , Apoptosis , Biomarcadores/sangre , Monitoreo Ambulatorio de la Presión Arterial , Estudios Transversales , Ecocardiografía , Femenino , Humanos , Hipertensión/sangre , Hipertensión/tratamiento farmacológico , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Inflamación/fisiopatología , Masculino , Persona de Mediana Edad , Miocitos Cardíacos/metabolismo , Insuficiencia Renal Crónica/diagnóstico por imagen , Insuficiencia Renal Crónica/fisiopatología , Remodelación Vascular

RESUMEN

Glaucoma (GL) and atrial fibrillation (AF) are diseases of significant social importance. Cardiovascular disorders such as systemic hypertension, hypotension, increased blood viscosity, vasospasm, and diabetes are potential risk factors of GL, especially when intraocular pressure is not elevated. Only a few studies have reported a possible connection between cardiac arrhythmias and GL. The purpose of this study was to evaluate the risk of GL in patients with AF.A total of 117 patients were included in the study, 79 with AF (AF group) and 38 with sinus rhythm (Control group), matched for age and sex. The mean ±â€Šstandard deviation age was 73.6 ±â€Š7.2 and 71.6 ±â€Š4.7 years for the AF and control groups, respectively. There were no statistically significant differences in the percentage of systemic hypertension, congestive heart failure, diabetes mellitus type 2, or vascular disease between the groups. Patients were examined for the presence of normal-tension glaucoma (NTG) by an ophthalmologist.NTG was confirmed in 40 patients (34.2%) in the entire group, with 35 (44.3%) in the AF group and 5 (13.15%) in the Control group. The incidence of NTG was significantly higher in the AF group (P = .0221). Women represented 60% of GL patients in the AF group and 80% in the control group. There were no significant differences in intraocular pressure between the groups (mean ±â€Šstandard deviation, 14.3 ±â€Š2.3 vs. 14.2 ±â€Š2.8 mmHg, P = .4202). Approximately three-fourths of patients with AF and NTG had early visual field damage based on the Hodapp classification.AF, independent of other known cardiovascular risk factors, increases the risk of developing NTG. Many AF patients do not have conspicuous symptoms of GL, so understanding the possible risk of its development is critical because early detection might help to prevent later visual impairment and even irreversible blindness.

Asunto(s)

Fibrilación Atrial , Glaucoma de Baja Tensión , Trastornos de la Visión , Anciano , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Fibrilación Atrial/fisiopatología , Diagnóstico Precoz , Intervención Médica Temprana/métodos , Femenino , Humanos , Presión Intraocular/fisiología , Glaucoma de Baja Tensión/complicaciones , Glaucoma de Baja Tensión/diagnóstico , Glaucoma de Baja Tensión/epidemiología , Glaucoma de Baja Tensión/fisiopatología , Masculino , Polonia/epidemiología , Medición de Riesgo , Factores de Riesgo , Estadística como Asunto , Tonometría Ocular/métodos , Trastornos de la Visión/etiología , Trastornos de la Visión/prevención & control

Asunto(s)

Drogas Ilícitas/efectos adversos , Metanfetamina/análogos & derivados , Intervención Coronaria Percutánea , Infarto del Miocardio con Elevación del ST/etiología , Infarto del Miocardio con Elevación del ST/cirugía , Stents , Adulto , Humanos , Masculino , Metanfetamina/efectos adversos , Polonia , Factores de Riesgo , Infarto del Miocardio con Elevación del ST/diagnóstico , Resultado del Tratamiento

RESUMEN

BACKGROUND: Progress in the management of myocardial infarction has contributed to the increased population of patients with asymptomatic left ventricular dysfunction or congestive heart failure. These patients are at high risk of sudden cardiac death. Factors that worsen this prognosis include exacerbation of coronary artery disease and acute coronary syndrome. We aimed to define and compare risk factors of acute coronary syndrome and sudden cardiac death as well as the cumulative incidence of both in patients after myocardial infarction with asymptomatic left ventricular dysfunction or congestive heart failure during a 2-year follow-up period. MATERIAL/METHODS: We enrolled 320 patients who survived the first 2 to 3 weeks after first ST-elevated myocardial infarction. Seventy-one patients who developed acute coronary syndrome and 38 who experienced sudden cardiac death were analyzed. RESULTS: In patients with asymptomatic left ventricular dysfunction, the only independent predictor of sudden cardiac death was male sex. Diabetes was the only predictor for acute coronary syndrome. In patients with chronic heart failure, low heart-rate variability was the strongest independent predictor of sudden cardiac death. Increased mean 24-hour heart rate was the most powerful predictor of acute coronary syndrome. The cumulative incidence of acute coronary syndrome and sudden cardiac death was most strongly associated with a total cholesterol level >200 mg/dL and increased QT-interval dispersion. CONCLUSIONS: Predictors of acute coronary syndrome and sudden cardiac death differ in patients after myocardial infarction with asymptomatic left ventricular dysfunction or chronic heart failure and are inconsistent at different stages of development of chronic heart failure.

Asunto(s)

Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/fisiopatología , Infarto del Miocardio/complicaciones , Infarto del Miocardio/fisiopatología , Sobrevivientes , Disfunción Ventricular Izquierda/complicaciones , Disfunción Ventricular Izquierda/fisiopatología , Síndrome Coronario Agudo/complicaciones , Síndrome Coronario Agudo/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Muerte Súbita Cardíaca/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Modelos Cardiovasculares , Análisis Multivariante , Polonia/epidemiología

RESUMEN

UNLABELLED: Presently a lot of studies focus on metabolic syndrome. There are new studies regarding the relationship between metabolic syndrome (MS) and changes in myocardial structure and function and subsequent development of heart failure. The aim of the study was to assess the myocardial structure and function, particularly diastolic function, and to evaluate the exercise capacity in patients with metabolic syndrome. MATERIAL AND METHODS: 53 patients with MS (defined according to NCEP ATP III criteria) and 33 individuals in control group were enrolled into the study. Echocardiographic examination (with evaluation of morphologic parameters, ejection fraction and diastolic function) and ergospirometry (to objectively assess the exercise capacity) were performed in all patients. RESULTS: In patients with MS hypertension (100%) and abdominal obesity (98%) were the most frequent. In the studied group significantly lower E/A ratio (describing left ventricle relaxation) was observed in comparison to control group (E/A 1.0 +/- 0.05 vs. 1.29 +/- 0.11; p < 0.05). Diastolic dysfunction assessed with the use of E/A worsened with the number of metabolic syndrome elements (1.07 vs. 0.96 vs. 0.87 for 3, 4 and 5 metabolic syndrome elements respectively). Lower peak oxygen uptake (VO2 peak) was observed in patients with MS in comparison to control group (24 +/- 0.75 vs. 27 +/- 1.52 ml/kg/min; p < 0.05). There was the tendency to higher VE-CO2 slope index in patients with MS in comparison to control group (27 +/- 0.45 vs. 25 +/- 0.7; p = 0.057). VE-CO2 slope increased with the increase of the number of MS elements (26 vs. 28 vs. 29 for 3, 4 and 5 metabolic syndrome elements). There was significant positive correlation between E/A ratio and VO2 peak (r = 0.27; p < 0.05) and significant negative correlation between E/A ratio and VE-CO2 slope (r = -0.37; p < 0.01). CONCLUSIONS: In patients with metabolic syndrome the significant decrease of exercise capacity assessed by ergospirometry and lower values of E/A ratio (that describes left ventricle relaxation) in comparison to control group. It seems that there is casual relation between these parameters and one may conclude that patients with MS are at risk of development of left ventricle dysfunction and in consequence heart failure.

Asunto(s)

Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Síndrome Metabólico/complicaciones , Síndrome Metabólico/diagnóstico , Miocardio/patología , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/etiología , Diástole , Ecocardiografía , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/patología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Espirometría , Disfunción Ventricular Izquierda/patología

RESUMEN

INTRODUCTION: Prognosis in patients (pts) after myocardial infarction (MI) with chronic heart failure (CHF) and asymptomatic left ventricular dysfunction (ALVD) differs. Acute coronary syndromes (ACS) worsen CHF and prognosis in these pts. A diagnostic tool that identifies the group of high risk pts is needed. Prognostic factors include left ventricle ejection fraction (LVEF) and stage of heart failure. The aim of the study was evaluation if decreased LVEF worsen prognosis in pts with CHF and ALVD and whether LVEF is more powerful predictor of poor prognosis than severity of heart failure. MATERIAL AND METHODS: 112 consecutive pts (95 men and 17 women age range 34-75, mean 52.9) post MI in stage B (ALVD) or stage C (CHF) according to ACC/AHA classification were studied. LVEF was determined in standard echocardiography with Simpson's method. Pts were divided into four groups: I--stage B and LVEF < or = 40% (6 pts); II--stage B and LVEF > 40% (52 pts); III--stage C and LVEF < or = 40% (19 pts); IV--stage C and LVEF > 40% (35 pts). The pts were followed for 30 months for the occurrence of the composite endpoint: major acute coronary events (MACE) i.e: ACS and cardiovascular deaths (CVD). In analysis we used chi2 test. RESULTS: There were 35 MACE during follow-up: 30 in pts in stage C and 5 in stage B. There were more MACE in group I than in group III (p < 0.01) and in group II than in group IV (p < 0.001). Pts in group I had more MACE than in group IV (p < 0.05). There were more MACE in group II than in group III (p < 0.01). Other results were not statistically significant. CONCLUSIONS: Stage of heart failure evaluated clinically is more powerful predictor of MACE than decreased LVEF. The more advanced stage of heart failure in post-MI pts, the higher risk of ACS or CVD. LVEF does not influence the risk of MACE in pts in the same stage of heart failure.

Asunto(s)

Causas de Muerte , Insuficiencia Cardíaca/mortalidad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Disfunción Ventricular Izquierda/fisiopatología , Adulto , Anciano , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Enfermedad Crónica/epidemiología , Enfermedad Crónica/mortalidad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/epidemiología , Infarto del Miocardio/fisiopatología , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo , Volumen Sistólico

RESUMEN

UNLABELLED: Silent myocardial ischaemia (SMI), a common disorder, has been studied by different research groups for the last 25 years. It is known that SMI is more common in patients with type 2 diabetes mellitus (type 2 DM) than in the general population, even though pathological mechanisms responsible for SMI are unclear. The aim of the study was to assess the role of SMI and other conditions in predicting adverse outcome in patients with type 2 DM during five years of follow-up. MATERIALS AND METHODS: 67 males with type 2 DM were enrolled into the study group. 55-healthy men were used as a control group (CG). Precise clinical examinations (medical history, physical examination, laboratory tests) were conducted. Coronary risk factors and the level of diabetes control were assessed. Noninvasive cardiological tests: ETT, 24 h ECG and echocardiography were performed. The prevalence of the following complications: ischaemia, unstable angina, myocardial infarction, heart failure, death and need for invasive procedures was recorded for five years. Parameters responsible for the complications were analyzed with the use of univariate logistic regression test; odds ratio was calculated. RESULTS: The silent myocardial ischaemia was found in 32.8% of patients with type 2 DM and in 9.1% men in control group (p < 0.001). The complications were observed in 24% of men with DM and in 16% in control group (NS). It was found that 25 parameters in the studied group and 16 parameters in the control group were statistically significant for the prediction of complications (among analyzed 92 parameters). The most important of them in type 2 DM group are: duration of diabetes (years) OR--1.18 (p < 0.01), fasting glucose (mg/dl) OR--1.017 (p < 0.01), SMI episodes (ETT) OR--4.72 (p < 0.01), diastolic dysfunction (E/A), OR--0.003 (p < 0.02) and left ventricle hypertrophy OR--3.86 (p < 0.05), whereas in CG--SMI episodes, OR--17.72 (p < 0.002). CONCLUSIONS: (1) The silent myocardial ischaemia is common in patients with type 2 DM. It was diagnosed in 33% of the patients. (2) The presence of SMI significantly increases the risk of complications both in patients with diabetes mellitus and the control group. (3) There are many other factors predisposing to the complications. In patients with diabetes mellitus they included, besides SMI, the duration of diabetes, chronic hyperglycemia and left ventricular diastolic dysfunction.

Asunto(s)

Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/diagnóstico , Adulto , Anciano , Angina Inestable/diagnóstico , Angina Inestable/etiología , Estudios de Casos y Controles , Intervalos de Confianza , Diabetes Mellitus Tipo 2/epidemiología , Electrocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/etiología , Isquemia Miocárdica/epidemiología , Oportunidad Relativa , Polonia/epidemiología , Prevalencia , Medición de Riesgo , Factores de Tiempo , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/etiología